1. Field of the Invention
The present invention relates to a latch, and more particularly to a cylinder lock assembly that has an exterior housing, a core casing set and a core and indicates a user that the core and the core casing set are released and are ready to be detached when the user rotates the core to a specific angular position.
2. Description of Related Art
Cylinder lock assemblies are generally used in homes and offices, are mounted on doors to lock the doors. When a key for a cylinder lock assembly on an entrance is missed or a tenant holding the key moves out from a rental house, the cylinder lock assembly needs to be replaced. However, conventional cylinder lock assemblies are non-detachable so replacing the cylinder lock assemblies spends time and money.
With reference to FIGS. 10-13, a detachable cylinder lock assembly has been developed in order to avoid spending too much time and money in replacing the cylinder lock assembly on a door. The detachable cylinder lock assembly has a corresponding key (90) and comprises an exterior housing (60), a core casing (70) and a core (75).
The key has a notch (91).
The exterior housing (60) is cylindrical and has a central hole (61), a first channel (62), a second channel (63) and a mounting hole (64).
The central hole (61) is defined longitudinally through the exterior housing (60).
The first channel (62) is defined in the exterior housing (60) and communicates with and extends radially out from the central hole (61).
The second channel (63) is defined in the exterior housing (60) and communicates with and extends radially out from the central hole (61).
The mounting hole (64) is defined radially in the exterior housing (60) and communicates with the second channel (63).
The core casing (70) is longitudinal, is mounted slidably in the central hole (61) in the exterior housing (60) and has a front end, a rear end, a core hole, a faceplate (701), a top protrusion (71) and an inclined protrusion (80).
The core hole is defined longitudinally through the core casing (70).
The faceplate (701) is formed on the front end of the core casing (70).
The top protrusion (71) extends radially up from the core casing (70), is mounted slidably in the first channel (62) in the exterior housing (60) and has multiple outer bores (711), multiple outer tumblers (74), a cover (72) and multiple springs (73). The outer bores (711) are defined through the top protrusion (71) and communicate with the core hole. The outer tumblers (74) are slidably mounted respectively in the outer bores (711). The cover (72) is mounted on the top protrusion (72) and covers the outer bores (711). The springs (73) correspond respectively to the outer tumblers (74), are mounted respectively in the outer bores (711) and each spring (73) is mounted between a corresponding outer tumbler (74) and the cover (72).
The inclined protrusion (80) is formed on and protrudes radially from the core casing (70), is inclined up, is mounted slidably in the second channel (63) and has a longitudinal slot (81), a mounting slot (811), a retaining tab (82) and a biasing fastener (84). The longitudinal slot (81) is defined in the inclined protrusion (80). The mounting slot (811) is defined radially through the inclined protrusion (80), corresponds to the longitudinal slot (81), is aligned with the mounting hole (64) in the exterior housing (60) and communicates with the core hole in the core casing (70). The retaining tab (82) is mounted slidably through the mounting slot (811) and has a through hole (83) defined through the retaining tab (82). The biasing fastener (84) is resilient and U-shaped, is mounted in the longitudinal slot (81) and extends through the through hole (83) in the retaining tab (82) to fasten the retaining tab (82) in the mounting hole (64) in the exterior housing (60) and the mounting slot (811) in the inclined protrusion (80). Therefore, the core casing (70) is mounted securely in the exterior housing (60) by the retaining tab (82).
The core (75) is cylindrical, is mounted rotatably in the core hole in the core casing (75) and has a front end, a rear end, a keyhole (76), multiple inner bores (77), multiple inner tumblers (78), a recess (761), a driving shaft (85) and a mounting collar (86).
The inner bores (77) are defined radially in the core (75), correspond respectively to the outer bores (711) in the core casing (70) and respectively receive the outer tumblers (74) partially when aligned respectively with the outer bores (711).
The inner tumblers (78) are slidably mounted respectively in the inner bores (77) and are pushed inward respectively by the outer tumblers (74) when the inner bores (77) are aligned respectively with the outer bores (711).
The recess (761) is defined radially in the core (75), communicates with the keyhole (76) and corresponds to the notch (91) in the key (90).
The driving shaft (85) is formed on the rear end of the core (85) and may drive a door handle as the core (75) rotates.
The mounting collar (86) is mounted around the core (75) and abuts the rear end of the core casing (70) to prevent the core (75) from falling out of the core hole.
When the key (90) is inserted into the keyhole (76), the inner tumblers (78) are moved out to push the outer tumblers (74) back into the outer bores (711) so the core (75) may rotate freely in the core hole to open the door. When the core (75) is needed to be replaced, rotating the key (90) in the keyhole (76) to align the recess (761) in the core (75) with the mounting slot (811) in the inclined protrusion (80) causes the retaining tab (82) to engage with the recess (761) and the notch (91) in the key (90). In the engagement with the recess (761), the retaining tab (82) moves entirely out of the mounting hole (64) in the exterior housing (60) and the core casing (70) and the core (75) are released. Therefore, pulling the key (90) detaches the core casing (70) and the core (75) out from the exterior housing (60).
However, the rotation of the core (75) by the key (90) is smooth without any blocking feelings corresponding to the alignment of the recess (761) and the mounting slot (811) so that people would not be indicated that they have already achieved the specific angular position to detach the core casing (70).
To overcome the shortcomings, the present invention provides a cylinder lock assembly to mitigate or obviate the aforementioned problems.